Model Output Discussions 12z 03/05/2016

[mb018538]

Runs aren't quite as good this morning - last nights UKMO was a blinder - but aren't without note. ECM still has 850s of 16c for Sunday, with the warmer air holding on in the south. The North doesn't look as good, potentially quite wet and windy for a time, and not as warm.

[mb018538]

That said, there is good agreement that once this temporary high pressure is pulled back out into the Atlantic, a nasty low pressure is show across the UK by midweek on both GFS and ECM - UKMO looks similar too, so expect a similar outcome:





From summer to autumn in 2 days - welcome to the UK!

[bluearmy]

Runs and ens are drifting away from a decent spell of weather next week (more so the south). depends what happens in the west Atlantic  and how amplified the ridge becomes. More amplified will drop the upper trough notably into nw Europe as our ridge retro grades. No surprise then that  ECM is a bit keener than gfs though they are quite well aligned day 8. the broad pattern of the summer thus far seems quite well entrenched. 

very surprised to see TS on the 10 day N24 forecast predicting a warm and settled spell mid Aug. See no evidence anywhere for that. Latest ec46 looks more of the same with Scandinavia trough repeating around pulses on the AH ridge. 

[coldcomfort]

Well once again the ECM goes from hero to zero within 24hrs, thankfully I'm not sure too many of us got taken in by yesterdays 00 run, which always looked fanciful in the extreme. All in all a very disappointing but not entirely surprising set of runs this morning, with the back end of the ECM run suggesting temps low enough for some wet snow over the top of Ben Nevis.....oh the British summer!!!

[fine wine]

On a positive note this weekends warm spell across England has upgraded in terms of temperatures.

[March]

17 minutes ago, coldcomfort said:

Well once again the ECM goes from hero to zero within 24hrs, thankfully I'm not sure too many of us got taken in by yesterdays 00 run, which always looked fanciful in the extreme. All in all a very disappointing but not entirely surprising set of runs this morning, with the back end of the ECM run suggesting temps low enough for some wet snow over the top of Ben Nevis.....oh the British summer!!!

Yeah I'm pretty sure British weather is defined by the summit of Ben Nevis....

[Frosty.]

Why worry about next week when there is some cracking weather on the way for the south of the uk this weekend with potential for it to become very warm for a time. The south should become dry, warm and sunny this weekend into early next week but the north of the uk looks like staying unsettled and less warm. Temps could reach the 80's F in the south for a few days according to the gfs / ukmo / gem / ecm...nice to have good weather coinciding with a weekend..at least for England and Wales.

Edited August 2, 2016 by Karl.

[Man With Beard]

29 minutes ago, bluearmy said:

Runs and ens are drifting away from a decent spell of weather next week (more so the south). depends what happens in the west Atlantic  and how amplified the ridge becomes. More amplified will drop the upper trough notably into nw Europe as our ridge retro grades. No surprise then that  ECM is a bit keener than gfs though they are quite well aligned day 8. the broad pattern of the summer thus far seems quite well entrenched. 

very surprised to see TS on the 10 day N24 forecast predicting a warm and settled spell mid Aug. See no evidence anywhere for that. Latest ec46 looks more of the same with Scandinavia trough repeating around pulses on the AH ridge. 

They do seem to be a day or so behind - 36 hours ago the settled card looked quite good but D10-D15 now looking a bit of a lottery with just a brief topple from the mid-Atlantic high

ECM really has been all over place recently - having moved towards the GFS in the past 24 hours it now goes way beyond it with a mega-Scandi trough at T192. I think we're pretty set until Monday, after that, clearly less settled but not sure how much - HP could still get a bit closer from the W as the week goes on

[MP-R]

I'm not too worried about next week just yet, other than there must be high pressure over the UK 11th-14th August for the Bristol Balloon Fiesta. Next week's low is going to cause some headaches re how it behaves in relation to the high pressure. At present, it appears to stop the high from the southwest push too far north, so the best we could hope for in that situation is that the ridge flattens rather than pulls back into the Atlantic, at least then the southern half of the UK would be in with a chance of a continuation of settled conditions, not so good for the north however. The GFS shows exactly what we don't need to happen in August, and that is the low to sink straight through the UK, which in itself is quite an unusual synoptic for August but something that took place quite markedly in August 2014. All FI however.

Meanwhile, however, looks like an improving picture after today with Friday-Sunday looking good so far:

With the 10C isotherm over the UK, sunny conditions would readily bring 24-28C, perhaps a tad higher in urban areas. I'm just trying not to get too up or downbeat about next week just yet.

[Yarmy]

1 hour ago, bluearmy said:

Runs and ens are drifting away from a decent spell of weather next week (more so the south). depends what happens in the west Atlantic  and how amplified the ridge becomes. More amplified will drop the upper trough notably into nw Europe as our ridge retro grades. No surprise then that  ECM is a bit keener than gfs though they are quite well aligned day 8. the broad pattern of the summer thus far seems quite well entrenched. 

very surprised to see TS on the 10 day N24 forecast predicting a warm and settled spell mid Aug. See no evidence anywhere for that. Latest ec46 looks more of the same with Scandinavia trough repeating around pulses on the AH ridge. 

Yeah, commented on that in a status update. Relatively confident was the term used which made me sit up. so I had a quick look at the pub run and it was the polar opposite. MOGREPS perhaps indicating something. Has Ian F posted this summer? 

[bryan629]

11 minutes ago, Yarmy said:

Yeah, commented on that in a status update. Relatively confident was the term used which made me sit up. so I had a quick look at the pub run and it was the polar opposite. MOGREPS perhaps indicating something. Has Ian F posted this summer? 

Ian Fergusson ‏@fergieweather  Jul 31

W COUNTRY OUTLOOK 2/2 Into 2nd half, UKMO GLOSEA5 maintains idea of blocking across Scandinavia, resulting in more settled, warmer E'ly flow

[Man With Beard]

Pretty solid agreement on GEFS and ECM mean chart that, by next Wednesday, a cold front will have passed through, with cooler, showery conditions for all - best in S. No decent sign of settled weather after that.

  

The low headed towards us on Monday/Tuesday, not picked up until the last 36 hours, has killed the chances of a longer spell of settled weather next week, unfortunately. To be fair, the ECM ensembles never really got on board with the UK High idea, so it was never in the bag.

[coldcomfort]

1 hour ago, March said:

Yeah I'm pretty sure British weather is defined by the summit of Ben Nevis....

I think you know the point I was making. Frankly I'm not convinced about the so called cracking weekend ahead either. Looks to me as if there will be a lot of cloud around on Sat in what will be a fairly moist SW flow behind the WF, especially for northern and western areas, then on Sunday the CF moving south (albeit as a weakening feature) will also bring a fair amount of cloud. More runs needed as ever, but to my rather simplistic way of viewing things it's only going to be southeastern England that enjoys what most of us consider to be a fine, summery weekend. That said, compared to the last 24hrs and the next 24 to come I'll accept it with open arms.

[Frosty.]

This is all working out as the amazing Tamara said recently, expect short settled and warmer interludes to come along from time to time and one such interlude is on the way for the weekend. At this range if I drew a line from south Wales, the south Midlands across to east Anglia southward, the weekend and early next week look warm or very warm with plenty of sunshine and light winds. Tomorrow looks a decent day across most of England and Wales too with sunny spells and temps between 21-24c but it does look very breezy / gusty or windy even, especially in coastal parts of the southwest. Thursday looks like sunshine and heavy showers but then it's an improving picture further south.

[Frosty.]

The Gfs 6z op run shows a change to fine and warm weather across the south of the uk later this week, especially for the weekend and next monday as high pressure builds in close to the south with temps widely into the low to mid 20's celsius and locally low 80's F for a time in the s / se. The northwest of the uk looks more unsettled and cooler but with some fine and pleasantly warm days too. From next tuesday it becomes unsettled and much cooler from the north with unseasonably cool days and cold nights, even a risk of local air frosts in rural spots in parts of scotland. Further into low res apart from brief weak ridging in the south it looks trough dominated with subdued temperatures but it's only 1 run..plenty of opportunity for the mid August period to improve.

[mountain shadow]

Absolutely horrendous GFS 6z which is trough dominated with unseasonable low pressure and Northerlies. Hopefully just a one run blip and Fergieweathers Scandi High comes to fruition.

[Frosty.]

Just now, mountain shadow said:

Absolutely horrendous GFS 6z which is trough dominated with unseasonable low pressure and Northerlies. Hopefully just a one run blip and Fergieweathers Scandi High comes to fruition.

It's not horrendous its beautiful, the highest Scottish mountains might even get a dusting of snow next week and night frosts!..BOOM

[johnholmes]

If the latest 6-14 day anomaly charts from EC-GFS and NOAA are anything to go by then warm/hot/settled is not something to believe in sadly. They could be wrong, would not be the first time, we only have to look back 2-3 weeks, at least for the southern half of the UK and neither of the 3 suggested what happened. But I would not bet against the upper air pattern shown by them below.

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

That does not of course rule out the odd pleasant summery sort of day but not more than a blip really!

If it was winter the usual crowd would be almost beside themselves.

[mountain shadow]

1 minute ago, Karl. said:

It's not horrendous its beautiful, the highest Scottish mountains might even get a dusting of snow next week and night frosts!..BOOM

Your quite correct, I should have caveated my post as excellent charts for the Scottish Skiing industry.

[Frosty.]

2 minutes ago, johnholmes said:

If it was winter the usual crowd would be almost beside themselves.

I'm already beside myself..Boom!

[Frosty.]

16 minutes ago, mountain shadow said:

Your quite correct, I should have caveated my post as excellent charts for the Scottish Skiing industry.

I can only imagine how Greenland1080 enjoyed the Gfs 6z for next week.

[mb018538]

Those anomaly charts have to be some of the worst you can see in mid summer. Massive northerly plunge with high pressure out west, and low pressure east and over the UK.

Still, it's going to warm up mid month according to Tomasz Schafernaker, so let's just ignore this data.

[A.J]

25 minutes ago, Karl. said:

It's not horrendous its beautiful, the highest Scottish mountains might even get a dusting of snow next week and night frosts!..BOOM

....behave yourself Karl.....lol............

the plus side of the current output infers from an IMBY perspective a 3 day window of warm, potentially hot weather in a few days time

[Frosty.]

1 minute ago, mb018538 said:

Those anomaly charts have to be some of the worst you can see in mid summer. 

It's late summer now, anyway I would just say if you are in the south, enjoy the warm spell the 6z shows between Friday and Monday.

[Frosty.]

2 minutes ago, ajpoolshark said:

....behave yourself Karl.....lol............

the plus side of the current output infers from an IMBY perspective a 3 day window of warm, potentially hot weather in a few days time

Sorry aj i got carried away by a late summer northerly..time for my meds